Skip to main content
Ch 31: Alternating Current
Young & Freedman Calc - University Physics 14th Edition
Young & Freedman Calc14th EditionUniversity PhysicsISBN: 9780321973610Non è quello che usi tu?Cambia libro di testo
Capitolo 31, Problema 4b

A capacitor is connected across an ac source that has voltage amplitude 60.0 V and frequency 80.0 Hz. What is the capacitance C of the capacitor if the current amplitude is 5.30 A?

Guida verificata passo dopo passo
1
Start by understanding the relationship between the current amplitude (I), voltage amplitude (V), and the capacitive reactance (X_c) in an AC circuit. The formula is: I = V / X_c.
Recall that the capacitive reactance (X_c) is given by the formula: X_c = 1 / (2πfC), where f is the frequency and C is the capacitance.
Rearrange the formula for capacitive reactance to solve for capacitance (C): C = 1 / (2πfX_c).
Substitute the expression for X_c from step 2 into the equation from step 1: I = V / (1 / (2πfC)).
Rearrange the equation from step 4 to solve for C: C = I / (2πfV). Substitute the given values for I, f, and V to find the capacitance.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
2m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Capacitive Reactance

Capacitive reactance (Xc) is the opposition that a capacitor offers to the flow of alternating current (AC). It is inversely proportional to the frequency (f) of the AC source and the capacitance (C) of the capacitor, given by the formula Xc = 1/(2πfC). Understanding this concept is crucial for calculating the capacitance when the current amplitude is known.
Video consigliato:
Percorso guidato
08:02
Capacitors & Capacitance (Intro)

Ohm's Law for AC Circuits

Ohm's Law in AC circuits relates the voltage amplitude (V), current amplitude (I), and reactance (X) through the formula V = IX. For capacitors, this becomes V = IXc, where Xc is the capacitive reactance. This relationship helps determine the capacitance when the voltage and current amplitudes are given.
Video consigliato:
Percorso guidato
03:12
Resistors in AC Circuits

AC Circuit Analysis

AC circuit analysis involves understanding how components like capacitors behave under alternating current. Unlike DC circuits, AC circuits require consideration of phase differences and reactance. Analyzing these circuits involves using complex numbers and phasors to represent voltages and currents, which is essential for solving problems involving capacitors in AC circuits.
Video consigliato:
Percorso guidato
08:40
Impedance in AC Circuits